WARNING DEVICE AND WARNING METHOD

In related art, there has been a problem that it is difficult to enable a driver of a vehicle to appropriately perceive a detected pedestrian or the like. A warning apparatus (1) includes a first image acquisition unit (21) configured to acquire a first image photographed by a far-infrared camera (11) which performs photographing in an advancing direction of a vehicle, a second image acquisition unit (22) configured to acquire a second image photographed by a visible light camera (12) which performs photographing in a direction agreeing with a direction of the far-infrared camera (11), a detection unit (23) configured to detect an object as a warning target from the first image acquired by the first image acquisition unit, a range specification unit (24) configured to specify a first object range in the first image and to specify a second object range, which corresponds to the first object range and indicates the detected object in the second image, in a case where the detection unit (23) detects the object as the warning target, and a display control unit (25) configured to cause a display unit (14), by which the driver of the vehicle is capable of visual observation of the second image, to display the second image in which the second object range is drawn.